A:AB=AC
B:AD=BD
C:BE⊥AC
D:BE平分∠ABC
下列标点运用正确的一项是( )
—Don't worry. I'll have it __________.
(1)计算:823﹣2-12+232+(13)0
(2)已知a>0,且a﹣a﹣1=3,求值:①a2+a﹣2;②a3+a-3a2+a-2-3a4-a-4.